Page 12 - Estimators Piping Man Hour Manual

PREFACE

Updated with the addition of 26 new tables on pneumatic mechanical instrumentation,
this fifth edition is written for the majority of estimators who have not had the advan-
tages of years of experience and/or of being associated with a firm that spends thou-
sands of dollars for time studies and research analyses. I believe that the book will
decrease the chance of errors and help the partially experienced estimator to deter-
mine more accurately the actual direct labor cost for the complete fabrication and
installation of process piping for a given industrial or chemical plant.
This book is strictly for estimating direct labor in man hours only. You will not find any
costs for materials, equipment usage, warehousing and storing, fabricating, shop set-
up, or overhead. These costs can be readily obtained by a good estimator who can
visualize and consider job schedule, size, and location. If a material take-off is avail-
able, this cost can be obtained from vendors who will furnish the materials. These
items must be considered for each individual job.
The following direct man hours (or in the case of alloy and nonferrous materials, the per-
centages) were determined by gathering hundreds of time and method studies coupled
with actual cost of various operations, both in the shop and field on many piping jobs
located throughout the country, ranging in cost from $1,000,000 to $5,000,000. By careful-
ly analyzing these many reports, I established an average productivity rate of 70%. The
man hours or percentages compiled throughout this manual are based on this percentage.
I wish to call your attention to the introduction on the following pages entitled "Pro-
duction and Composite Rate," which is the key to this method of estimating.

The Human Factor in Estimating
In this high-tech world of sophisticated software packages, including several for labor
and cost estimating, you might wonder what a collection of man-hour tables offers that
a computer program does not. The answer is the human factor: In preparing a complete
estimate for a refinery, petrochemical, or other heavy industrial project one often con-
fronts 12-18 major accounts, and each account has 5-100 or more sub-accounts, depend-
ing on the project and its engineering design. While it would seem that such numerous
variables provide the perfect opportunity for computerized algorithmic solution, accu-
rate, cost-effective, realistic estimating is still largely a function of human insight and
expertise. Each project has unique aspects that still require the seasoned consideration
of an experienced professional, such as general economy, projects supervision, labor
relations, job conditions, construction equipment, and weather, to name a few.
Computers are wonderful tools. They can solve problems as no human can, but I do
not believe construction estimating is their forte. I have reviewed several construction
estimating software packages and have yet to find one that I would completely rely on.
Construction estimating is an art, a science, and a craft, and I recommend that it be
done by those who understand and appreciate all three of these facets. This manual is
intended for those individuals.
John Page
Houston, Texas